Problem:

• Product Name: Visibroker for C
• Product Version: 7.0 and above
• Product Component: Core ORB
• Platform/OS Version: RHEL 4.0
• JDK/Compiler Verison: n.a.

Setting thread stack size and default stack sizes of different operating systems

Resolution:

One can use dispatcher's "threadStackSize" property (of the corresponding Server Connection Manager under the corresponding Server Engine) to set thread stack's size. For instance, for the default iiop_tp SCM of iiop_tp SE, the property is "vbroker.se.iiop_tp.scm.iiop_tp.dispatcher.threadStackSize".

The default value is 0, which indicates system's default value and should be specified in bytes.

You have to note the following points before setting the threadStackSize:

1. Systems running a large number of thread stacks may need to set a smaller the thread stack size in order to improve performance.
2. The thread stack size should never be smaller than 128k. Setting the thread stack size smaller than this can result in a failure to allocate threads.
3. You need to ensure that that the system has sufficient stack segment allocated for the process.
4. This threadStackSize option affects only those threads that are created by the ORB to service CORBA requests. It does not affect the main thread or threads created by the application.
5. You have to estimate the stack size value based on the memory requirement of your application.
6. VisiBroker calls pthread_attr_setstacksize() API internally to set the thread's stack size when creating a new worker thread. The functions pthread_attr_setstacksize() and pthread_attr_getstacksize(), respectively, sets and gets the thread stack size.
7. The threadStackSize setting will only take effect on a spawned worker thread, and will not affect any other admin threads created by the orb. So, you can only see a change in the thread stack size if you examine the spawned worker threads servicing your servant.